String musical instrument



y 1936- F TURNER STRING MUSICAL INSTRUMENT Filed June 24, i932 2 Sheets-Sheet 1 31 PI aft 4o 39 1]\I'VENTUR May 26, 1936. F, TURNER 2,042,080

STRING MUSICAL INSTRUMENT Filed June 24, 1932 2 Sheets-Sheet 2 INVENTOR Patented May 26, 1936 UNITED STATES PATENT OFFICE '7 Claims.

This invention relates to improvements in stringed musical instruments, and one of its leading objects is to provide an instrument which will produce musical tones of high quality with a construction adapted to permit of low costs of manufacture, and which employs a diaphragm to amplify the tones produced.

Another object of the invention is to provide a stringed instrument with which musical tones of high quality may be produced in ample volume.

Another object of the invention is to provide a musical instrument with a diaphragm, which is supported in place so that it is protected against undesirable stresses and strains, and which will be of very light and yet efficient design.

A still further object is to provide an improved means for supporting the bridge of a string musical instrument, so that more desirable musical effects are produceable from the use of the instrument.

A more particular object of the invention is to provide a musical string instrument with a vibratable member or bar, upon which the string bridge is supported, and to which is attached or connected a diaphragm for amplifying the musical tones produced, a relatively large area of the vibratable member or bar being unrestrained by contact with the body or frame of the instrument.

With the above and other objects in view the invention consists in certain new and useful combinations, constructions, and arrangements of parts, clearly described in the following specification, and fully illustrated in the accompanying drawings, in which:-

Fig. 1 is a plan view of a complete instrument, embodying my invention.

Fig. 2 is a longitudinal sectional View, taken on line A, of Fig. 1, looking in the direction of the arrow, showing the construction and mounting of the diaphragm.

Fig. 3 is a transverse sectional view, taken on line B, of Fig. 1, looking in the direction of the arrow. v

Fig. 4 is a plan view of the body of another form of the instrument. 7

Fig. 5 is a longitudinal sectional view, taken on line C, of Fig. 4, looking in the direction of the arrow.

Fig. 6 is a transverse sectional View through another modified construction of the resilient bar.

Fig. '7 is a detail sectional view of 'Fig. 3, showing the means for supporting the resilient bar.

Fig. 8 is a detail plan view of Fig. '7.

Fig. 9 is a detail side elevation of Fig. 7.

Fig. 10 is a vertical sectional view showing another method of supporting the resilient bar.

Fig. 11 is a plan view of the body of an instrument shaped like a guitar.

Fig. 12 is a longitudinal sectional view, taken on line E, of Fig. 11, looking in the direction of the arrow.

Fig. 13 is a transverse sectional view, taken on line F, of Fig. 11, looking in the direction of the arrow.

Fig. 14 is a longitudinal sectional view through another modified form of the invention.

Fig. 15 is another plan view of another modified form of the invention.

Referring to the accompanying drawings illustrating the practical construction of my invention, 5 designates a body, constructed of ordinary wood or material, which of itself need not be selected for high vibrating qualities, and which comprises the relatively thin bottom wall 6, the side walls I and 8, the end wall 9, and the opposite end wall l0, all rigidly united to each other. The neck I l is suitably connected to the end wall l0 and is equipped with the usual frets l2, and the string tightening members l3, mounted to turn on the head [4.

The ends of the musical strings I6 are connected to the tail piece [1, which is attached to the end wall 9, and extend across the bridge [8, which is supported on the resilient bar or member l9, and thence across the frets of the finger board, in the usual manner to connect -with the adjusting devices l3 as shown.

The resilient bar i9 is constructed of wood or resilient material and is supported by the cross pieces 22 and 23, suitably attached to the side walls I and 8. The bar I5 is forced into place against the tension exerted by the rubber cushion blocks 20, and 2|, which are located in recesses a and Zla, formed in the side walls 1 and 8. The yielding rubber blocks allow a slight end play of the bar, when it vibrates.

The resilient vibrating bar or member I9 carries a conical diaphragm 24, which is constructed of paper, or other light material. The small end of this conical diaphragm is mounted by suitable adhesive on the disc 25, which is formed of cork or similar material, which is attached directly to the underside of the resilient bar or 0 member IS. The larger or open end of the coni- -cal diaphragm is spaced above the bottom wall 6, and away from the side and end walls of the sound box, so that there will be no restrain or in terference with its vibration, under the influence of the sound waves generated by the vibration of the music strings. This arrangement produces clear musical tones.

In Figs. 4 and 5, I show another construction of the sound box, the body of which is similar to that shown in Figs. 1 and 3, inclusive, except that in the showing of Figs. 4 to 5, two bars, 26 and 21 are arranged at right angles to each other, the opposite ends of the bar or member 26 being supported against the rubber or resilient blocks 28 and 29, on the side walls la and 8a, and the pposite ends of the bar or member 27 being supported against the rubber or resilient blocks 30 and 3|, on the side walls 9a and Illa.

A light conical diaphragm 32 is connected at its smaller end with the lower bar 21. The larger and bottom end of the diaphragm is supported by the annular member or ring 34, which may be made of thin leather, or other light flexible material, positioned between the retaining rings 35 and 36, of the inner sound box 31. This inner sound box is supported by the blocks 38 and 39 on the bottom of the outer box All, which is provided with a neck 4| of usual construction. The outer marginal edge portion of the lower end of the diaphragm is positively held in place with the aid of the screw bolts 42 which extend through the flexible connecting ring 34 and the cooperating rings 35 and 36.

In the construction shown in Figs. 4 and 5, the resilient member includes the two bars 26 and 21, the lower one of which carries the diaphragm, and the upper one of which carries the bridge 42. These bars are preferably adhesively attached at their intersection. In this embodiment the air waves are prevented from swirling around the edge of the diaphragm, thus improving the quality and increasing the volume of the tone produced. The vertical wall of the inner sound box 3! acts as a. baflie to increase the effective distance between the two sides of the diaphragm. The construction of the diaphragm and its peripheral mounting is very similar to that of a radio loud speaker. I consider a diaphragm of this type constructed of paper or other light material much superior to the aluminum diaphragms which have been previously used in instruments of this class. The strings and tail piece (not shown) may be arranged the same as those in Fig. 1.

In Fig. 6, I show another form of the invention, wherein the resilient member or bar is formed with a rising arch, to provide an arched spring bar 51. The ends of this bar are supported by the brackets 58 and 59, carried by the side walls 60 and 6|. The ends of the bar 51 engage the rub.- ber thrust blocks 66a and Bla. The neck of the paper diaphragm 62 is formed with tabs 62a, which are secured by adhesive to a circular disc of cork or light wood adhesively attached to the arched resilient bar or member 51. When the strings are tightened, it will bend from an arched position to a substantially straight line position. as indicated in dotted lines in the drawing. This form of bar may be used in various embodiments of the invention. v

In Figs. 7, 8, and 9, I show enlarged detail views of the support for the resilient member. It will be noted that the cross pieces 22 and 23 are formed with notches 22a, which receive the ends of the resilient member, and that the yielding rubber blocks or cushions 26 and 2| are subjected to slight compressive action. The notches 22a prevent lateral displacement of the resilient member, while the yielding rubber cushion blocks allow a limited end play, which permits the resilient member to more freely vibrate.

In Fig. 10, I show the resilient bar or member I!) firmly attached adhesively or otherwise on the cross pieces 22 and 23, against the end wall of the body of the instrument.

In Figs. 11, 12 and 13, I show an instrument of the type of the guitar, which includes the outer wall 63 and the longitudinal stiffening member 64. A resonant bottom wall 65 is fixed to the lower edge of the outer wall. A circular wall 66 is arranged within the outer wall 63, and to this circu lar wall the top wall 6? is secured. This top wall is provided with a relatively large opening 61a and a smaller opening 611), separated therefrom by the division bar 610. A resilient member or bar 68 is disposed across the opening 61a at right angles to the major axis of the body of the instrument, and on this member or bar the bridge 69 is positioned or secured. The lower circular edge of the conical diaphragm I6 is connected by the flexible ring H to the lower edge of the circular wall 66, while the neck or top of the diaphragm is connected in the usual manner to the resilient bar 68. In this embodiment the sound waves from the underside of the diaphragm escape through the opening Glb. An instrument of this type will have a greater amount of resonance than the forms previously shown and described.

It is not necessary that the two ends of a resilient bar shall be supported in the same manner thus one end may be rigidly supported as shown in Fig. 10 while the other end may be supported as in Fig. 7 to 9 also both ends may be unyieldingly supported as in Fig. 10 with little loss of efiiciency.

In Fig. 14, I show a longitudinal sectional view of an instrument which includes the box-like body 14, and which is provided with the thin resilient member or bar 15, supported at its ends by the cross pieces 16 and TI, and engaging the thrust rubber cushion blocks 18 and 79. The resilient bar or member 15 supports the resilient vertical rod 80, to the lower end of which the apex of the conical diaphragm BI is secured.

In Fig. 15, I show another construction of the instrument, wherein the circular body I 63 is provided with a resilient member I04, provided with a plurality of radial arms I05, which may be formed from thin flexible material. The meeting center of these arms supports the bridge Hi6 and the depending conical diaphragm I01.

It is obvious that in the various embodiments shown and described changes may be made in the type of resilient member used, thus in Figs. 1 to 3 a resilient member comprising more than one bar could be used while a single resilient bar could be substituted for the resilient member shown in Figs. 4 and 5. It is also evident that a resilient member such as is shown in Fig. 15 could be substituted for the types shown in Figs. 1, 4, and 11. Also a longitudinally arranged bar as shown in Fig. 14 could be used in place of the bars shown in Figs. 1 and 11 while a diaphragm arranged as in Fig. 14 could be used in the other embodiments shown, with or without a peripheral support.

The resilient members or bars may be of any light resilient material, but I prefer Wood which term is intended to cover woody substances, as for example cane or bamboo. The member or bar should be stiff enough to hold the centre of the diaphragm in its desired position; in some embodiments it may be the sole support of the diaphragm. At the same time it should be resilient enough to vibrate at an amplitude suitable for sound and music production. For an instrument such as is shown in Fig. l supposing the diaphragm to be nine inches in diameter the resilient bar of spruce wood which is very suitable may be ten inches long, three fourths of an inch wide and average one quarter of an inch in thickness being slightly thicker in the centre than at the ends though this last is not necessary. These dimensions may vary widely, thus if a smaller number of strings are used the bar may be lighter while a considerably heavier bar will give a tone of smaller volume. The phrase resilient member is intended to cover all the forms shown and described whether consisting of one or more resilient bars.

The diaphragm may be made of any suitable material, and may be other than of conical shape. In fact, any form of diaphragm which will serve the purpose, may be employed in cooperation with the resilient member.

The term frame or body is intended to include any supporting structure, which carries the resilient member.

Various changes may be resorted to, over those illustrated and described, within the scope of the invention, as defined in the claims annexed hereto.

I claim as new and patentable:

1. A stringed musical instrument including a hollow body, string connecting and tensioning means arranged on the body, a resilient member supported on the body at its outermost portions only and having its inner portion free to vibrate, a bridge supported on an inner vibratable portion of the resilient member, strings stretched over the body and engaging the bridge, and a diaphragm positioned in the body and operatively connected to an inner portion of the resilient member adjacent to the bridge mounting.

2. A stringed musical instrument having a hollow body, a resilient bar supported by its end portions on the body and having its intermediate portion free to vibrate, a diaphragm positioned beneath the resilient bar and having its central portion connected to an intermediate vibratable portion of said bar, a bridge supported on the bar over the diaphragm connection, and strings stretched over the body and in engagement with the bridge.

3. A stringed musical instrument having a hollow body, a resilient member having its outermost portions only supported by the body and having its central portion capable of vibration in a direction substantially perpendicular to the plane of the top of the body, a diaphragm positioned beneath the resilient member and operatively connected to a central portion of said member, a bridge supported on a central portion of the resilient member, and strings stretched across said bridge and in contact therewith.

4. A stringed musical instrument including a hollow body, a bar-shaped resilient member extending across the top of the body and havin bearing therewith only at its end portions and being unrestrained from vibration at all points between said end portions, a bridge supported on a central vibratable portion of said member, strings stretched over the body and engaging the bridge, and a conical type diaphragm positioned below the resilient member and having its apex portion connected to a central portion of the resilient member.

5. A stringed musical instrument having a body providing a chamber, a resilient wood bar having end portions only supported on the body to support said bar across the chamber, a bridge mounted on substantially the center of said bar, strings stretched over the body and engaging the bridge, and a diaphragm positioned in the body, said diaphragm being operatively connected to a central portion of the resilient wood bar.

6. In a stringed musical instrument, a hollow body, a resilient member extending across the top of the body, being supported on the body at its outermost portions only and having its central portion capable of vibration in a direction substantially perpendicular to the plane of the top of the body, a diaphragm in the body beneath the resilient member and supported at its periphery on said body, means connecting the central part of the diaphragm with the central part of the resilient member, and a bridge supported on a central part of said resilient memher.

'7. A stringed musical instrument including a hollow body, a plurality of strings stretched longitudinally over said body, a resilient wood bar having its end portions only supported on the body and extending across the body at substantially right angles to the strings, the central part of said bar being capable of vibration in a direction substantially perpendicular to the plane of the strings, a diaphragm positioned in the body beneath the resilient bar, means connecting the central part of the diaphragm with the central part of the resilient wood bar, and a bridge supported on the central part of said bar for engaging the strings.

FRANK TURNER. 

